import java.util.HashMap;
import java.util.Map;

//sum 0f two numbers
class Solution{
    public int[] twoSum(int[] nums,int target){
        Map<Integer,Integer> map = new HashMap<>();
        for (int i = 0; i < nums.length; i++) {
            int complement = target - nums[i];
            if (map.containsKey(complement)) {
                return new int[] {map.get(complement),i};
            }
            map.put(nums[i], i);
        }
    }
}